The initial phase of developing a thermal shape-memory blood-clot filter for the human vena cava has resulted in clarification of the properties of the Nitinol alloy, arrangements for obtaining suitable Nitinol material for experimental purposes, improvements, in filter design and construction and improved means of analyzing the transformation process of actual filters. It is now proposed to move into the next stage of the project. This will focus medically on the effectiveness of the filter, the bioacceptability of the Nitinol material as well as the effects of the body fluids on the filter, and improvements in the filter handling and insertion procedures. On the materials side we plan further characterization of the properties of the Nitinol material to refine alloy fabrication, wire processing and filter construction, storage and transport.